A sensor system for measuring a velocity of a fluid flowing through a channel includes a heating element for heating the fluid. The interface comprises electronic coupling pads, in particular resistive contact pads, with corresponding coupling elements of the reader, and transmitting andor receiving means for electromagnetic waves, in particular an antenna, designed to enable communication with the contactless electronic device. The seal cap also includes an attachment ring that is selectively detachable therefrom for selective attachment of a retractor. Capture arms on the tethered homing signal seeking UUV engage the capture cable and guide the capture cable to one of several cable snagging eye-members. A tool package is formed when the upper and lower adaptors are abuttingly engaged along the downwardly and upwardly facing contact surfaces.